This is because the sound you make when you say x is ex thus using a but when you make the b sound it sounds like be.
Answer:
-It's natural that some people are slaves
-Slaves are inferior beings
-Slavery is good for slaves
-Abolishing slavery would threaten the structure of society
a. like
it says Like in the second line.
Like and as are used for similes. Thats why it cant be B or D and it doesnt say as so A. Like would be the answer.